Use a smallstring instead of an std::string in FileChanged to avoid some malloc traffic.

This speeds up -E on xalancbmk by 2.4%

llvm-svn: 40461

1 files changed, 11 insertions, 0 deletions

diff --git a/clang/Lex/Lexer.cpp b/clang/Lex/Lexer.cpp
index f23d34ed422..c45a36a9a59 100644
--- a/clang/Lex/Lexer.cpp
+++ b/clang/Lex/Lexer.cpp
@@ -92,6 +92,17 @@ std::string Lexer::Stringify(const std::string &Str, bool Charify) {
   return Result;
 }
 
+/// Stringify - Convert the specified string into a C string by escaping '\'
+/// and " characters.  This does not add surrounding ""'s to the string.
+void Lexer::Stringify(llvm::SmallVectorImpl<char> &Str) {
+  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+    if (Str[i] == '\\' || Str[i] == '"') {
+      Str.insert(Str.begin()+i, '\\');
+      ++i; ++e;
+    }
+  }
+}
+
 
 //===----------------------------------------------------------------------===//
 // Character information.